Contrast-Associated Acute Kidney Injury and Serious Adverse Outcomes Following Angiography

Background: Contrast-associated acute kidney injury (CA-AKI) associates with an increased relative risk for serious adverse outcomes. However, the magnitude of this risk and the incidence of clinically significant CA-AKI derived from analyses of large cohorts with prospective assessment of CA-AKI and subsequent outcomes are unknown. Objectives: This study sought to characterize the relative risk for and incidence of serious adverse outcomes following the development of CA-AKI and to explore whether CA-AKI mediates the association of pre-angiography estimated glomerular filtration rate with adverse outcomes. Methods: Among 4,418 participants in the PRESERVE (Prevention of Serious Adverse Outcomes Following Angiography) trial with comprehensive baseline and outcome data, we assessed whether CA-AKI was associated with the 90-day outcome comprising death, need for dialysis, or persistent impairment in kidney function. We calculated the incidence of clinically significant CA-AKI (i.e., proportion of patients who developed CA-AKI and the 90-day outcome) and examined whether CA-AKI was a mediator of the association of baseline kidney function with the 90-day outcome. Results: CA-AKI was associated with an increased relative risk for 90-day death, need for dialysis, or persistent kidney impairment (odds ratio: 3.93; 95% confidence interval: 2.82 to 5.49; p < 0.0001). The incidence of clinically significant CA-AKI was 1.2% (53 of 4,418 patients). CA-AKI was not a mediator of the association of pre-angiography estimated glomerular filtration rate with the primary outcome. Conclusions: Whereas CA-AKI is associated with an increased relative risk of serious, adverse 90-day outcomes, the incidence of clinically significant CA-AKI is very low. CA-AKI does not mediate the association of the pre-angiography estimated glomerular filtration rate with these outcomes.